;(function ($) {
    $.fn.navfix = function (mtop, zindex) {
        var nav = $(this), mtop = mtop, zindex = zindex, dftop = nav.offset().top - $(window).scrollTop(), dfleft = nav.offset().left - $(window).scrollLeft(), dfcss = new Array;
        dfcss[0] = nav.css("position"), dfcss[1] = nav.css("top"), dfcss[2] = nav.css("left"), dfcss[3] = nav.css("zindex"), $(window).scroll(function (e) {
            $(this).scrollTop() > dftop ? $.browser.msie && $.browser.version == "6.0" ? nav.css({
                position: "absolute",
                top: eval(document.documentElement.scrollTop),
                left: dfleft,
                "z-index": zindex
            }) : nav.css({
                position: "fixed",
                top: mtop + "px",
                left: dfleft,
                "z-index": zindex
            }) : nav.css({position: dfcss[0], top: dfcss[1], left: dfcss[2], "z-index": dfcss[3]})
        })
    }
})(jQuery)